One day before Twitter's highly anticiplated IPO, a rumor surfaced that Jack Dorsey's other start-up darling, Square, might go public as early as next year.

The Wall Street Journalreported Wednesday that "a person familiar" with the situation claims the mobile payments company has had exploratory discussions with banks, including Goldman Sachs and Morgan Stanley. However, The Journal reports this source cautioned the company has not hired a bank yet--and Square declined to comment on the rumor all together.

Though Dorsey has said that the company is not yet profitable, The Journal reported some interesting numbers about this fast-growing company. The company should reportedly reach $550 million in sales by the end of the year, but as much as 80 percent of the company's revenue goes back to credit card companies. The Journal's source put the net revenue "closer to $110 million to $165 million."

Dorsey launched Square in 2009 by giving out the square-shaped card readers for free, and the San Francisco-based company quickly took off. In addition to getting high-profile partnerships, including ones with Starbucks and the City of New York, the company has $340 million in total financing from venture capital firms Kleiner Perkins and Sequoia Capital.